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<h2><a name="Letterbox"></a>Letterbox</h2>
<p><code>Letterbox </code>(<var>clip, int top, int bottom, [int left], [int right], int 
  &quot;color&quot;</var>)</p>
<p><code>Letterbox</code> simply blackens out the top <i>top</i> and the bottom <var>bottom</var>,
and optionally <var>left</var> and <var>right</var> side of each frame. 
This has a couple of uses: one, it can eliminate stray
video noise from the existing black bands in an image that's already letterboxed;
two, it can eliminate the garbage lines that often appear at the bottom of the
frame in captures from VHS tape.
</p>
<p>The functionality of <code>Letterbox</code> can be duplicated with a combination
of <code><a href="crop.htm">Crop</a></code> and <code><a href="addborders.htm">AddBorders</a></code>, but
<code>Letterbox</code> is faster and
easier.
</p>
<p>Generally, it's better to crop this stuff off using <code>Crop</code> 
or <code><a href="crop.htm">CropBottom</a></code>
than to hide it with <code>Letterbox</code>. However, in some cases, particularly
if you're compressing to MPEG, it's better to use <code>Letterbox</code>
because
it lets you keep a standard frame size like 352x288 or 320x240. Some MPEG players
get confused when the source video has a strange frame size.
</p>
<p>The color parameter is optional, default=0 &lt;black&gt;, and is specified as
an RGB value regardless of whether the clip format is RGB or YUV based.
See <a href="../syntax_colors.htm">here</a>
for more information on specifying colors.
</p>
<p>
Another use could also be to clear out overscan areas in VCD or SVCD encodings.
<p><kbd>$Date: 2008/06/06 11:37:04 $</kbd></p>
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